steam jet propulsion engines

[Guest]

steam jet propulsion engines...........does anyone know any current info on this technology.....i.e. when will they be manufacturing products?

http://www.pursuitdynamics.com/default.asp

[ted655]

As soon as they find a safe, reliable, economical, light weight, fuel eficient steam generator.. Around 2018.:eek:

[Andrew]

How about burning Hydrogen? End result is very very very hot steam. Wouldn't that work?

[yipster]

http://www.ilc-usn.net/conversions/propuls/shtlref/mengflow.gif

[Andrew]

Haha, there we go. A miniature hydrogen rocket engine for your boat! Does anybody know the volume and pressure of steam required in order to make a boat go anywhere with the proposed (not the rocket engine) steam jet drive?

[yipster]

if your not ganna ask them (http://www.newscientist.com/news/news.jsp?id=ns99993321) i might, before you know it they sell it out as fire extinguisher... (http://www.newscientist.com/news/news.jsp?id=ns99994738)
http://www.newscientist.com/data/images/ns/9999/99994738F1.JPG
from the pulsejet forum "pulsed outboard": "Sorry jets don't push against air or water etc. The propelling force is due to hurling as much stuff away as fast as possible (Rockets work better in a vaccum). As an example jet boats squirt the water from the jet unit out above the water line. The New Zealand built Hamilton jet unit only worked once this was done and of course three people claim to have been the one who sugested the obvious on the vital day." so for boat propulsion i think its a little different beam i guess.

[marinedummy]

they are been used sometimes after a gas turbine in a couple of ships the now. rollls royce are looking in to it. i thing its called cogas something

[Thunderhead19]

Actually Hydrogen peroxide and calcium chlorate will generate a healthy supply of superheated steam. Enough to send a several thousand pound projectile across the english channel I seem to recall. They used this process(in that same era) in steam turbines to get experimental u-boats to do over 26kts.

[fredrosse]

I think these are only "pipe dreams"

[artemis]

I think these are only "pipe dreams"
No, no Fred. First patented in the 1840s by a Frenchman. Called an injector. Using boiler pressure it will pump water into the same boiler. Don't quite understand what these people have to patent though. :D

Ron Fossum

[fredrosse]

Steam injectors for boiler feed, as well as steam jet eductors for bilge pumps, boiler ash ejection, and steam jet air ejectors for maintaining condenser vacuum have all been around for more than a century. These devices are used more for convenience (lack of moving parts, intermittent duty) and generally use only a small fraction of available steam on a steam propelled boat or ship.

The reference to the "Steam Jet Boat Propulsion" device as "Pipe Dreams" is in regard to propulsion efficiency by use of such a device. It must be a very very inefficient application of steam power for main propulsion.

The steam jet type pumps are very inefficient to start with, generally being much less efficient than typical small steam engines. They are even less efficient at moving large quantities of water for propulsion.

As we know, decent propulsion efficiency requires the movement of large quantities of water, so the steam jet system seems to have two strikes against it.

[artemis]

My remarks were meant facetiously and to point up the absurdity of such a harebrained idea. :D

[yipster]

I think these are only "pipe dreams"
you may be rite but nothing wrong with that. allready boats/ships are entering the jet age. turbines and impellors or how will that develop?
reading ion jets (http://www.boatdesign.net/forums/showthread.php?t=6245) and vortex stuff (http://enstrophy.colorado.edu/~mohseni/VortexDynamics1.html) always make me think how that would fit us boaters.